7 - UCY
Multidisciplinary Architectural design optimization
The main objective of the work package is to use coordination methods for multidisciplinary design optimization (MDO) of buildings with emphasis on structural and environmentally benign engineering. Furthermore, in this work package we intend to investigate and propose interdisciplinary design methodologies towards topologically optimized structures with regard to architectural and engineering disciplines concerned. Such multidisciplinary design approaches are primary influenced by the interrelated disciplines, the process of design, its iteration and integration steps involved, horizontally by the platforms of digital design, computation and fabrication applied. Computational platforms of operation and realtime performance simulators provide meanwhile robust visualization and feedback features that can be associated with geometrical digital design models and numerical optimization. Design developments at various stages encompass further parametric investigations with regard to form, material and structure. In this respect, a redefinition of design objectives and procedures is needed in respective developments . At the same time, integration processes within the design process suggest a reconsideration of the working boundaries of interrelated disciplines, like for example architecture and engineering.
WP4 - Multidisciplinary Architectural design optimization [Months: 4-36]
Energy-efficient building design requires analysis that involves multiple disciplines. When the coupling among these disciplines is strong and/or when the associated design optimization problems are large (number of variables can/or constraints), monolithic solution approaches may be inadequate. In such cases, decomposition-based multidisciplinary design optimization (MDO) formulations are required, which in turn necessitate appropriate coordination strategies to account for the interactions among the decomposed, yet linked, disciplinary problems to ensure that the obtained solutions are consistent. In this WP, we will tailor a non-hierarchical coordination method that was developed for simulation-based engineering design to the needs of building structural engineering and energy systems. This method was an extension of a hierarchical methodology called analytical target cascading (ATC) that was originally developed to support requirements management in product development. The non-hierarchical extension removed the restrictive hierarchy assumption and made the method amenable to solving general MDO problems. It has been used in the past mostly in automotive and aerospace engineering applications, but its usefulness has been demonstrated in other application domains, including manufacturing systems and limited applications to civil engineering design problems. Such problems have modest problem sizes. The main challenge that this research will address is dealing with structural problems that involve much larger numbers of variables and/or constraints. The numerical behaviour of the coordinating scheme, based on using augmented Lagrangian penalty functions and method of multipliers updating schemes, will be investigated and enhanced as necessary. In addition, the formulation of the design problems will be adjusted to allow for solving shape and topology optimization problems. Previous applications of the non-hierarchical ATC method considered traditional “sizing” design optimization problems. Therefore, the appropriateness of problem formulations for fundamentally different design problems as well as associated optimization algorithms must be assessed. Based on the researchers’ for 15 year experience in MDO, while the principles of coordination methods and strategies are standard, the implementation details vary substantially from problem to problem and application domain to application domain. Therefore, extending the applicability of nonhierarchical MDO coordination methods to building design is a novel and significant contribution to all pertinent fields. The process of interdisciplinary design directly related to structural performance, enables investigation, development and effective management of the complexity of the systems through modelling and simulation processes of interrelated form, structural components and materials. The development of topologically optimized structures may be achieved on the basis of performance-based design, primarily formulated through individual discipline criteria, or performanceoriented design, following nonlinear processes in achieving most appropriate design solutions as to multiple criteria [5, 6]. Furthermore, a bottom-up approach may be followed, when the structure typology, the geometrical and structural restrictions of the system are iteratively determined. On the other side, a top-down approach refers to the design of structures conceived from initial conceptual stages, following certain performance evaluation criteria [7, 8]. The investigation of different modes of design operation and interactive development of the disciplines involved, comprise the following Tasks of the WP: Page 16 of 48 Task 4.1: Investigations on Methodologies of Multidisciplinary Design The WP will be initiated with a systematic investigation of case examples and interdisciplinary design methodologies of structures in architecture. Key aspects of performance-based and -oriented design will be identified and investigated together with the implicated modes of operation with regard to the nonlinearity and iteration degree of the design process . In this frame, continuous design iterations dealing with creativity, accuracy, optimization and realization may respectively represent different phases of the design process, including a conceptual design phase, detailed phases and fabrication. Throughout the development, a number of in-between development phases constitute the process of iterative design refinement, while any design process may be repeated until a desirable solution is achieved. This implies that any development from concept to detail and fabrication may be re-evaluated within a performative context in a nonlinear way, i.e. by moving from the conceptual to the detailed design phases and the fabrication, and the other way round. In parallel to such nonlinear approaches within the design process realized through certain cyclic interdisciplinary design steps, also interactivity within the decisions making processes provides further levels of operation modes . Such iterative steps of multidisciplinary design, verification and optimization will be examined, for the definition of related developing processes that may further define influencing values and parameters of topologically optimized structures. Task 4.2: Digital Parametric Aided Design In this task, the application of Digital Parametric Aided Design principles, that are used as the platform of operation towards the design optimization of structures, and related case studies will be reviewed and discussed further, suggesting in parallel possible directions of investigation. The relatively new area of Digital Parametric Aided Design allows the effective design development of any complex and non-standard architectural and structural system . This, in combination with the ability of specific tools to effectively develop and model the morphology and behaviour of architectural and structural systems [11, 12], which are influenced by internal or external conditions (e.g. structural, environmental, etc.) allow their flexible and dynamic control during the optimization process. A procedure that can be characterized as an open-ended, whereas the results are not fixed but continuously changeable, allowing modifications of the initial morphology until final solutions are achieved. This can be applied in various stages of the process including the early conceptual and the detailed design stages , leading to optimized solutions according to performance-based and/or –oriented design criteria. Within this framework, Digital Parametric Aided Design tools will be applied for: a) 3D modelling and geometrical development of suggested structural morphologies, b) Morphological and behavioural control of structures during the process of optimization, c) Dynamic and real time analysis of structures based on building performance criteria. Aim is the real time evaluation of structures’ performance according to the selected criteria in a continuous feedback loop process leading to the best possible morphological solutions in each case study. Task 4.3: Manufacturing This task will be concentrated on the investigation and development of physical prototyping mechanisms that can be applied in various scales of suggested architectural and structural systems aiming at further evaluation according to their constructability, their ability to be easily assembled as well as according to their static performance. The numerical control of construction processes is considered as an indispensable part of the Digital Parametric Aided Design investigation due to the ability of fabrication mechanisms to be effectively used for the manufacturing of complex and non-standard morphological outcomes . Towards this direction, an initial investigation into possible fabrication mechanisms will be reviewed, discussing their limitations and potentials  as well as their ability to be applied in manufacturing as part of an additive or subtractive fabrication process . Within this framework, 3D rapid prototyping, CNC laser cutting, as well as robotically driven fabrication methodologies will be reviewed. Then, according to the case study under investigation, fabrication strategies will be suggested taking into consideration in each case, the ability of machines to be effectively applied in order to achieve desirable outcomes based on the selected scale of investigation. 3D printer technology can be used in the early stage of process where small scale prototypes for visualization purposes are necessary to be developed. Then, laser cutter technology can be applied due to its ability to allow flexibility with regard to the selection of appropriate material as well as its large working area, allowing large scale prototypes close to the actual scale of structures to be developed. Finally, for actual scale prototypes, robotically driven technology can be used, offering the capability to the users to respond and find solutions according to specific manufacturing demands and material selection . The integration of different end-effectors to the robotic machine, for instance router for milling purposes, gripper for assembling as well as other custom made end-effectors for subtractive or additive fabrication purposes, can allow structural accuracy and reduction of manufacturing defects . Finally, the advantages and disadvantages of selected manufacturing techniques in each case study will be discussed and their performance will be evaluated. Task 4.4: Engineering Optimization Recent developments in the area of digital modelling of architectural and structural systems and their ability to be integrated with performance analysis platforms of operation allow investigation towards the best possible solutions that satisfy morphological, architectural, structural or other criteria from the early conceptual design stage. This is found to be useful especially due to the current design demands where multi-objective design criteria are involved. In this task, technological developments in the area of digital modelling and analysis will be reviewed, discussing their potential Page 17 of 48 to be used towards engineering optimization. Particularly, the current ability of digital design tools to be integrated with engineering platforms, aiming to be used in the initial stage of design investigation will be presented. Also, the ability of such mechanisms to be used for the dynamic development and control of complex morphologies and their ability to actively participate in the performance evaluation of buildings and structures using analysis software (finiteelement analysis, environmental analysis software, etc.) will be demonstrated [17, 18]. Finally, the way in which different digital design and performance analysis platforms are integrated as part of the engineering optimization process will be exemplified in a number of case studies where different criteria of investigation are specified. Task 4.5: Performance-based Multidisciplinary Design for Topology Optimization Aspects of integration of related disciplines involved in performance-based and -oriented multidisciplinary design will be investigated (e.g. architecture, structural and construction, environmental and material science disciplines) and applied in design case examples aiming at structural topology optimization, primarily to be achieved from different discipline areas and design iteration steps. In this frame, the syntax of multidisciplinary design following processes of topology optimization will be examined and methodologies of nonlinear design development and integration will be evaluated with regard to their efficiency of integration, development and performance achieved within the final results. Partic